NHM Marsupial Skin Data Analysis
Jen Ball, Bruno Cassanova, Ellen Coombs, Emma Dunne, & Aislinn Pearson
19th May 2017
Fat-tailed Mouse Opossum Thylamys
Introduction
Meet Thylamys, the fat-tailed mouse opossum from South America!
Thylamys pallidor
We collected body measurements of 73 individuals from four species of Thylamys in NHM Mammal collection and analysed the results…
Thylamys is a genus of marsupial from South America:
## Map from URL : http://maps.googleapis.com/maps/api/staticmap?center=-27.84356,-61.96&zoom=3&size=640x640&scale=2&maptype=terrain&language=en-EN&sensor=false
1. Which species is the cutest longest?
## Analysis of Variance Table
##
## Response: Total_length
## Df Sum Sq Mean Sq F value Pr(>F)
## Species 3 55763 18587.6 35.052 9.699e-14 ***
## Residuals 67 35529 530.3
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1##
## Call:
## lm(formula = Total_length ~ Species, data = marsupial)
##
## Residuals:
## Min 1Q Median 3Q Max
## -52.714 -11.739 2.235 15.500 53.714
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 238.000 5.757 41.341 < 2e-16 ***
## Specieskarimii -83.286 10.435 -7.981 2.6e-11 ***
## Speciespallidior -48.235 6.981 -6.909 2.2e-09 ***
## Speciesvenustus -2.714 8.427 -0.322 0.748
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 23.03 on 67 degrees of freedom
## (2 observations deleted due to missingness)
## Multiple R-squared: 0.6108, Adjusted R-squared: 0.5934
## F-statistic: 35.05 on 3 and 67 DF, p-value: 9.699e-142. Does altitude affect size?
## Analysis of Variance Table
##
## Response: Total_length
## Df Sum Sq Mean Sq F value Pr(>F)
## Altitude 1 1082 1081.6 0.7971 0.3753
## Residuals 64 86838 1356.8##
## Call:
## lm(formula = Total_length ~ Altitude, data = marsupial)
##
## Residuals:
## Min 1Q Median 3Q Max
## -107.42 -21.98 -10.96 34.60 85.11
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 211.094983 7.530169 28.033 <2e-16 ***
## Altitude -0.003133 0.003509 -0.893 0.375
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 36.84 on 64 degrees of freedom
## (7 observations deleted due to missingness)
## Multiple R-squared: 0.0123, Adjusted R-squared: -0.003131
## F-statistic: 0.7971 on 1 and 64 DF, p-value: 0.37533. Is there a relationship between the length of hind foot and body?
## Analysis of Variance Table
##
## Response: Hind_foot
## Df Sum Sq Mean Sq F value Pr(>F)
## Head_body 1 118.627 118.627 70.7803 6.775e-12 ***
## Species 3 50.922 16.974 10.1278 1.556e-05 ***
## Head_body:Species 3 8.642 2.881 1.7187 0.1722
## Residuals 63 105.588 1.676
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1##
## Call:
## lm(formula = Hind_foot ~ Head_body * Species, data = marsupial)
##
## Residuals:
## Min 1Q Median 3Q Max
## -4.4653 -0.6587 -0.0086 0.7369 5.0076
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 7.68237 2.44989 3.136 0.00260 **
## Head_body 0.06756 0.02066 3.271 0.00174 **
## Specieskarimii 0.53827 3.16268 0.170 0.86540
## Speciespallidior 0.23726 3.39545 0.070 0.94451
## Speciesvenustus 6.53074 3.17774 2.055 0.04402 *
## Head_body:Specieskarimii -0.03329 0.02995 -1.111 0.27061
## Head_body:Speciespallidior -0.01213 0.03303 -0.367 0.71459
## Head_body:Speciesvenustus -0.05891 0.02748 -2.144 0.03593 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 1.295 on 63 degrees of freedom
## (2 observations deleted due to missingness)
## Multiple R-squared: 0.6279, Adjusted R-squared: 0.5866
## F-statistic: 15.19 on 7 and 63 DF, p-value: 1.872e-114. Do males and females differ in size?
Sample size = 37 males, 36 females.
Conclusions
We acknowlegde the significiant limiations of our research, but onwards and upwards to greater data sampling!
(Not a mouse opossum, but equally cute)